def add_end(L=None):
	if L == None:
		L = []
	L.append('End')
	return L

print(add_end())
print(add_end([123]))
print(add_end())

def f1(a, b, c=0, *args, **kw):
	print('a = ', a, 'b = ', b, 'c = ', c, 'args = ', args, 'kw = ', kw)

def f2(a, b, c=0, *, d, **kw):
	print('a = ', a, 'b = ', b, 'c =', c, 'd = ', d, 'kw =', kw)

f2(1, 2, d='abc', city='hangzhou')
f1(1, 2, 4)
f1(1, 2, 3, 'c=3')